Abstract: An address space switching apparatus has a group of conventional registers capable of storing address information and a group of additional registers capable of storing address information longer than the address information stored by the group of conventional registers. The register length of the group of additional registers is not restricted by the length of the group of conventional registers and is selected to be of a magnitude sufficient to define a desired operand address space. Information items stored in the group of additional registers such as a base address and an index value associated with the extended address space are selected when an operand address is to be generated so as to be appropriately employed for the address computation, thereby supplying address information having a length sufficient for the extended address space.

Abstract: In a memory system having a storage device and a key storage keeping key data controlling an access to the storage device, there is disposed a key address translation structure for obtaining an address of an entry of the key storage based on an address of the storage device to which an access request is issued. As a result, when subdividing the storage device according to the key data setting unit, each subdivided area can be assigned with a variable size and a plurality of sizes are enabled to be specified for the key data setting units at the same time.

Abstract: An information processing apparatus having an address translation system includes a plurality of processors in each of which an addressing is carried out by translating a logical address into a real address in the virtual storage system for data processing. The plurality of processors include a scalar processor for translating a logical address into a real address by using an address translation table; and a vector processor for determining if the logical address to be relocated lies within a predetermined address range, for address-relocating the logical address to the real address based on a relocation table when the logical address lies within the predetermined address range, and using the logical address as a real address when the logical address lies outside of the predetermined address range. The predetermined address range and the content of the relocation table are set by the scalar processor which supervises the program storage area.